The regulating member of a timepiece generally includes an inertia wheel, called a balance, and a resonator called a hairspring. These parts have a determining role as regards the working quality of the timepiece. Indeed, they regulate the movement, i.e. they control the frequency of the movement.
The balance and the hairspring are different in nature, which makes it extremely complex to manufacture the regulating member, said manufacturing including the manufacture of the balance, the balance spring and the resonant assembly of the two parts.
The balance has thus been manufactured in various materials, but without resolving the isochronism difficulties that are linked to a temperature change in the regulating member on which the balance depends.